<?php
/**
 * Created by PhpStorm.
 * User: zhangrxiang
 * Date: 2017/6/27
 * Time: 21:02
 */

$html = file_get_contents('2.html');
//echo $html;

$preg = "/<div id=\"cnblogs_post_body\">.*?<\/div>/si";
preg_match($preg,$html,$match);
var_dump($match);